import numpy as np

x_first = np.array([1,2,3,4])
w = np.array([3,4,5,7])
y_first = x_first @ w
print(y_first)

x_second = np.array([2,5,6,7])
y_second = x_second @ w
print(y_second)

X = np.array([[1,2,3,4],
              [2,5,6,7]])
y_total = X @ w.reshape(4,1)
print(y_total)